• Korean Journal of Veterinary Research
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• v.33 no.1
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• pp.81-85
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• 1993

Gel electrophoresis has proven to be one of the most useful of DNA separation and purification. The new technique of pulsed field gel electrophoresis (PFGE) is high resolution separation of large size DNA moleculs. Conventional continuous gel electrophresis can not be separation of large DNA fragments(20~50 k base). Field inversion gel electrophoresis(FIGE) is very useful for large DNA molecules. We have found that a pulse ratio ; 2 : 1, time ; 24hrs., volts ; $10^{volts}/_{cm}$, start ; 0.45sec, end ; 1sec, is most effectively resolves DNA fragment in the 6~50k base.

• Bulletin of Food Technology
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• v.22 no.3
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• pp.502-512
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• 2009

• Biomedical Science Letters
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• v.11 no.2
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• pp.121-128
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• 2005

A total of 30L monocytogenes strains from different sources including 13 strains isolated from the foreign imported meat were genotyped in order to establish their genetic relatedness and to compare them with the foreign isolates. PFGE analysis of genomic DNA showed the $11\~16$ fragments ranging in size from 38 to 504 kb. Eleven different PFGE types $(1\~11)$ were identified in the dendrogram at $75\%$ similarity, and the two major PFGE types, type 1 and 2, contained $94\%$ of domestic isolates (16/17). All isolates from domestic beef and pork carcass were grouped in each different type, however, isolates from chicken were clustered together with those from pork and beef. We also found all foreign strains were unrelated with each other, regardless of geographic criteria and that they could be differentiated from those from the domestic isolates by PFGE pattern. The PFGE pattern of one isolate from chicken wing, which the chicken meat was found to be imported from foreign country, was closely related to that of isolate from the Thailand.

• Korean Journal of Veterinary Research
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• v.39 no.4
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• pp.811-818
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• 1999

A total of 16 Staphylococcus epidermidis isolates collected from 14 dogs admitted to the Veterinary Medicial Teaching Hospital in Seoul National University over eleven months were examined for in vitro antibiotic susceptibility pattern with minimum inhibitory concentration (MIC) and slime production, a virulence-associated phenotype, and were genetically characterized by pulsed-field gel electrophoresis (PFGE). The frequency of resistance to antimicrobial agents tested was not high, with a susceptibility ranging from 56.3% to 100%. Three strains exhibited multiple drug resistance against amikacin (MIC, $32-64{\mu}g/ml$), ampicillin ($32{\mu}g/ml$), fosfomycin ($32-128{\mu}g/ml$) and gentamicin ($16{\mu}g/ml$). Vancomycin, ciprofloxacin and rifampin were effective antibiotics against the isolates. All isolates were slime producers ; strains isolated from dogs which died of bacteremia were more likely to produce slime than those isolated from dogs which survived. Chromosomal DNA fingerprinting of the isolates yielded 16 different genomic types with few common bands, indicating a variety of clones of S epidermidis were prevalent in the hospital. This study revealed that PFGE is an useful method for the genotype characterization of S epidermidis strains and this organism could probably be pathogenic in some dogs with severe disorders. Further works on a larger number of epidemiologically defined strains are required to assess these results.

• The Journal of the Korean Society for Microbiology
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• v.35 no.4
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• pp.289-297
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• 2000

Background: Staphylococcus aureus (s. aureus) and Escherichia coli (E. coli) are major pathogens in community and hospital. And they sometimes cause the outbreak in hospital in the immunocompromised patients. Pulsed-field gel electrophoresis (PFGE) has been regarded as a standard method for genotyping in epidemiologic studies, but it is laborious and time-consuming. Infrequent restriction site-polymerase chain reaction (IRS-PCR), a new genotyping methods, was performed to compare the applicability with PFGE. Methods: We performed PFGE and IRS-PCR on S. aurues (n=120) and E. coli (n=117) which were collected clinically in 4 different hospitals. We assessed each method in terms of discriminatory power, quality, and efficiency. Results: In E. coli, the discriminatory power of IRS-PCR was $46.7{\sim}86.7%$, and that of PFGE was $88.9{\sim}96.7%$ according to hospital. But in S. aurues, the discriminatory power of IRS-PCR was $20{\sim}56.7%$, and that of PFGE was $40{\sim}90%$ according to hospital. The typablity and reproducibility of IRS-PCR were 100% of each. PFGE needed four days to complete the procedure, but IRS-PCR could be performed within one day, IRS-PCR showed better resolution than PFGE. Conclusion: In case of gram negative bacteria (like E. coli), IRS-PCR could be a reliable alternative for epidemiologic typing due to better efficiency and comparable discriminatory power. But in the case of gram positive bacteria (like S. aureus), IRS-PCR does not seem to be suitable for the strain-to-strain differentiation. More trials and changes of restriction enzymes or primers could reveal the efficacy of IRS-PCR in the field of molecular typing.

• Korean Journal of Veterinary Service
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• v.32 no.2
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• pp.155-163
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• 2009

Fowl typhoid (FT) is a septicemic disease caused by Salmonella Gallinarum. The purpose of this study was to investigate the antimicrobial resistance and pulsed-field gel electrophoresis (PFGE) patterns of S. Gallinarum isolated from chicken. During 1999 to 2004, there was isolated a total of 100 strains in liver and spleen. The biochemical characteristics of S. Gallinarum isolates was nonmotile, no production of H$_2$S, glucose gas, non-fermented rhamnose, indole-negative, fermentation of dulcitol, mannitol, maltose, and ornithine decarboxylase. At antimicrobial susceptibility, all of isolates were susceptible to amoxicillin/clavulanic acid, amikacin, neomycin, kanamycin, norfloxacin and enrofloxacin. One hundred isolates were divided into 54 resistant patterns and 37 strains was 6-multi drug resistance. PFGE of Xba I restriction fragments of S. Gallinarum isolates was 20 patterns.

• Journal of Microbiology
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• v.35 no.3
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• pp.172-176
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• 1997

The Mycobacterium tuberculosis clinical isolates in Korea, showing different drug resistances, were analyzed by comparing large restriction fragment (LRF) patterns produced y digestion of genomic DNA with infrequent-cutting endonucleases of SpeI, AsnI and pulsed-field gel electrophoresis (PFGE). SpeI and AsnI allowed with AsnI and SpeI, strains yielded an absolutely identical pattern for Korean type's mycobacteria even though they showed different drug resisstance. However, when three M. tuberculosis strains, showing drug resistance, were digested with XbaI, patterns were different from those of the other M. tuberculosis strians which are susceptible to drugs. This stuyd reveals that the comparison of chromosomal restriction patterns is very useful as an additional aid for the differentiation and identification of M. tuberculosis strains showing drug resistances.

• The Journal of the Korean Society for Microbiology
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• v.35 no.2
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• pp.171-180
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• 2000

Ninety two strains of Streptococcus pyogenes were isolated from patients with pharyngitis, scarlet fever, skin infection, and invasive streptococcal infections in Seoul, Korea from January to December, 1998. All isolates were epidemiologically characterized by T protein serotype, and serum opacity factor (OF) detection to phenotypes. To analyze the genetic relationship, fifty two isolates including 32 erythromycin-clindamycin (Em-Cm) resistant strains, 20 antimicrobial susceptible strains were attempted to the pulsed-field gel electrophoresis (PFGE). T protein serotype showed 16 kinds in distribution including T12 and T4. Among the total isolates, 40 strains (43.5%) belonged to the T12 serotype and twenty strains (21.7%) to T4 serotype. On the other hand, when infection aspect of S. pyogenes isolates were analysed by T serotype distribution, T12 type was predominant for pharyngitidis which contributed to 21 strains (53%) and for skin infection isolates which contributed to 11 strains (28%), respectively. In case of T4 type, it was the most predominant pharyngitidis isolates which contributed to 8 strains (40%). In T serotype distribution of Em-Cm resistant strains, 27 strains (84%) of the thirty two showed T12 serotype. In minimum inhibitory concentration (MIC) values of Em-Cm resistance isolates, thirty two isolates showed resistant to erythromycin 27 strains (84%), had high MIC of >$128\;{\mu}g/ml$. And also to clindamycin, twenty two strains (69%) had high MIC of >$128\;{\mu}g/ml$. When OF detection of Em-Cm resistance of S. pyogenes isolates were analyzed by T serotype distribution, T12 serotype isolates revealed that all of the isolates except one strain were OF negative. In PFGE profile analysis to Em-Cm resistance isolates, of the twenty seven, Em-Cm resistance of T12 serotype isolates, 26 strains showed identical PFGE profile and all of these isolates revealed that OF negative. Eighty four percent of Em-Cm resistance S. pyogenes isolates had identical phenotype and PFGE profile. These results strongly suggested that the Em-Cm resistant S. pyogenes isolates from Seoul area showed close genetic correlation and PFGE could be available tool for molecular epidemiology.

• Korean Journal of Veterinary Service
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• v.24 no.3
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• pp.243-253
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• 2001

Forty-five Salmonella typhimurium isolates were encountered 8 phage types in which DT197 and U302 were the predominant types. The DT104 type which was first found from pig in Korea, and was resistant to chloramphenicol, streptomycin, sulfamethoxazole/trimethoprim, tetracycline, gentamicin and nalidixic acid. Twenty-two S enteritidis isolates were encountered 5 phage types in which PT4 were the representative (predominant). S enteritidis isolates were susceptible to all antimicrobial agents. As a result of PFGE analysis for S typhimurium and S enteritidis, PFGE patterns was better than phage typing in discriminating of strains. PFGE patterns were not in accord with phage type even though some strain had the same phage types.

• Korean Journal of Veterinary Service
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• v.29 no.3
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• pp.297-308
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• 2006

Fowl typhoid (FT) is a septicemic disease caused by Salmonella gallinarum. The purpose of this study was to investigate the antimicrobial resistance and pulsed -field gel electrophoresis (PFGE) patterns of S gallinarum isolated from broiler. During 1999 to 2004, there was isolated a total of 26 strains in liver and spleen. The biochemical characteristics of S gallinarum isolates was nonmotile, no production of $H_2S$, glucose gas, non-fermented rhamnose, indole-negative, fermentation of dulcitol, mannitol, maltose, and ornithine decarboxylase. At antimicrobial susceptibility, all of isolates were susceptible to amoxicillin/clavulanic acid, amikacin, neomycin, kanamycin, and cephalothin. Twenty-six isolates were divided into 19 resistant patterns and 6 strains was 8-multi-drug resistance. PFGE of Xba I restriction fragments of S gallinarum isolates was 22 patterns.